Influence of nociceptive stimulation on analgesia nociception index (ANI) during propofol-remifentanil anaesthesia.

BACKGROUND: Measurement of the balance between nociception and anti-nociception during anaesthesia is challenging and not yet clinically established. The Surgical pleth index (SPI), derived from photoplethysmography, was proposed as a surrogate measure of nociception. Recently, the analgesia nociception index (ANI) derived by heart rate (HR) variability was developed. The aim of the present study was to challenge the ability of ANI compared with SPI to detect standardized noxious stimulation during propofol-remifentanil anaesthesia. METHODS: After Ethics approval and informed consent, 25 patients were anaesthetized with propofol [bispectral index (BIS) 30-60]. A laryngeal mask (LMA) was inserted and remifentanil stepwise increased to effect-site concentrations (Ce(remi)) of 0, 2, and 4 ng ml(-1). At each step, tetanic stimulation (STIM) was applied. ANI, SPI, BIS, HR, and mean arterial pressure (MAP) were obtained before and after LMA insertion and each STIM. Analysis was performed using Wilcoxon rank tests and calculation of prediction probabilities (P(K)). RESULTS: ANI and SPI, but not BIS, HR, or MAP, were significantly (P<0.05) changed at all examined steps. ANI response to STIM was (median [IQR]) -24 [-12-35], -30 [-20 - -40] and -13 [-5 - -27] at 0, 2 and 4 ng ml(-1) Ce(remi). However, prediction of movement to STIM was not better than by chance, as P(K) values were 0.41 (0.08) for ANI and 0.62 (0.08) for SPI. CONCLUSIONS: The two variables, ANI and SPI, enabled consistent reflection of stimulation during propofol-remifentanil anaesthesia. Nevertheless, ANI and SPI may improve detection but not prediction of a possible inadequate nociception-anti-nociception balance. Clinicaltrials.gov Identifier. NCT01522508.

Clinically relevant asymmetry of bispectral index during recovery from anaesthesia for ear-nose-throat surgery in adults and children.

This study investigates the incidence of clinically relevant asymmetry in bispectral index readings from different sides of the skull (using two monitors) during ear-nose-throat surgery in 42 adults and 46 children. A unilateral increase or decrease > 10% from baseline was defined as an 'asymmetry'. Asymmetry followed by movement after stimulation was defined as a 'clinically relevant asymmetry'. Asymmetry occurred in 39 out of 42 adults (93%) and in 20 out of 46 children (44%) during surgery and in 24 out of 42 adults (57%) and in 17 out of 46 children (37%) during recovery. Clinically relevant asymmetry was observed in 5 out of 42 adults (12%) and 6 out of 46 children (13%). The incidence of asymmetry was higher in adults during surgery (p = 0.0002). In conclusion, clinically relevant bispectral index asymmetry has been observed in > 10% of paediatric and adult anaesthesia and may have clinical implications. You can respond to this article at http://www.anaesthesiacorrespondence.com.

Effect of propofol and sevoflurane on acid-base balance during pediatric heart catheterization.

BACKGROUND: Propofol is routinely used for anesthesia during pediatric heart catheterization. Propofol infusion syndrome (PRIS) is a rare, but often fatal complication mainly defined as bradycardia with progress to asystolia during propofol infusion. Metabolic acidosis is regarded as an early warning sign of PRIS. In this study the effect of propofol and sevoflurane on serum base excess, pH and lactate have been examined during pediatric heart catheterization. METHODS: In this prospective randomised study 42 children have been anesthetised for pediatric heart catheterization with propofol (N.=22) or sevoflurane (N.=20) with ethic committee approval. Base excess, pH and lactate were measured by blood gas analysis at the beginning, during and at the end of the procedure. Changes relative to baseline were analysed by paired t-Test with correction for multiple testing. The study was powered to detect a difference of 1.5 mmol.L-1 for base excess and lactate. RESULTS: Base excess (-2.59 [2.33] vs. -4.48 [2.88], P=0.0004, mean [standard deviation]) and pH (7.39 [0.05] vs. 7.36 [0.06], P=0.0008,) changed significantly in in the propofol group but not in the sevoflurane group. The number of patients with base excess < 5.0 increased in the propofol group only from 2 to 10 (P=0.016). Lactate decreased in both groups (1.1 [0.3] vs. 0.9 [0.2], P=0.003 for sevoflurane and 1.0 [0.3] vs. 0.8 [0.3], P=0.0004 for propofol). CONCLUSION: Propofol but not sevoflurane had an effect on base excess and pH during pediatric heart catheterization.

Airway management in pediatric patients using the Glidescope Cobalt®: a feasibility study.

BACKGROUND: Video laryngoscopes are claimed to improve airway management. Several studies showed an equal or better glottic view using the Glidescope® compared with direct laryngoscopy in adults and in paediatric patients. Many case reports also described successful intubation in patients with a difficult airway. The Glidescope Cobalt® is a modified Glidescope® with a disposable sheath. Data on clinical application in paediatric patients is insufficient. METHODS: Twenty-four pediatric patients with a mean age of 27 months [range, 1-142] undergoing general anesthesia were included into this feasibility study. Cormack and Lehane grade was evaluated using a Macintosh blade. Tracheal intubation was performed using the Glidescope Cobalt®. Number of attempts, time to intubation, Cormack and Lehane (C&L) grade and a subjective score were noted for both a resident and an attending anesthesiologist. RESULTS: With the Glidescope Cobalt® the C&L grade improved in all patients with grade 2 or 3 to 1 and deteriorated in one case from C&L grade 1 to 2. The C&L grade remained unchanged in 15 patients (62.5%). C&L grades between resident and attending anesthesiologist were equal. Tracheal intubation was successful in 92% with a stylet-armed tube and in 8% using an unarmed tube with a Magill forceps, respectively. Time to intubation was median 50.5 [range, 22-93] seconds. CONCLUSION: The Glidescope Cobalt® presented suitable for use in children. C&L grade was significantly improved in all patients with a C&L grade of 2 or 3. Especially for educational purposes in pediatric anesthesia it provides a good view for all participants.

Electrophysiologic neuromonitoring during repair of the thoracoabdominal aorta by anesthesiologists.

BACKGROUND: Surgical repair of the thoracoabdominal aorta is associated with risk of spinal ischemia. Electrophysiologic neuromonitoring reduces this risk, but is usually performed by neurophysiologists not always available. In this study repair of the thoracoabdominal aorta monitored by anesthesiologists has been investigated. METHODS: Somatosensory and transcranial electrical motor evoked potentials were monitored in 20 patients. A lumbar intraspinal fluid drainage was inserted. Dacron graft replacement of the aorta was performed by sequentially clamping during partial cardiopulmonary bypass. Loss or decrease of amplitudes of evoked potentials of more than 50% prompted reinsertion of spinal arteries in the graft. RESULTS: One patient not monitored with motor evoked potentials due to indwelling cardiac pacemaker had postoperative paraplegia. Somatosensory and motor evoked potentials were recordable in all other patients. Two patients died during surgery, one patient died postoperatively. No surviving patient monitored with somatosensory and motor evoked potentials had neurologic deficits. CONCLUSION: Electrophysiologic neuromonitoring during surgical repair of the descending aorta can be successfully provided by anesthesiologists and should be predominately encouraged where neurophysiologists are not available due to organizational or financial shortcomings.

Propofol infusion syndrome: update of clinical manifestation and pathophysiology.

Propofol infusion syndrome (PRIS) is defined as acute bradycardia progressing to asystole combined with lipemic plasma, fatty liver enlargement, metabolic acidosis with negative base excess >10 mmol l(-1), rhabdomyolysis or myoglobinuria associated with propofol infusion. The purpose of this review was to provide a new update of reported case reports and to describe recent retrospective studies and animal research relevant for the pathophysiology and clinical presentation of PRIS. New case reports of PRIS have confirmed previously identified risk factors, and have also further revealed the incidence of PRIS in patients previously not estimated to be at risk for this syndrome. Retrospective studies contributed new evidence to the incidence of PRIS and development of PRIS even at propofol doses commonly used for surgical anesthesia. An animal study confirmed potential pathophysiological pathways and showed new organ manifestations possibly associated with propofol infusion. Further clinical and experimental evidence has confirmed the existence of PRIS as a rare but highly lethal complication of propofol use not limited to prolonged use of propofol. PRIS has to be kept in mind if propofol is used for anesthesia or sedation. Recommendations for the limitation of propofol use have to be adhered to. Early warning signs must prompt immediate cessation of propofol infusion and adequate treatment.

Autoantibodies with a protective function: polyreactive antibodies against alkaline phosphatase in bacterial infections.

In patients with acute bacterial infections antibodies directed against a particular bacterial antigen were detected. The molecular mass of this bacterial antigen was 50 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. By comparison of the NH2-terminal amino acid sequence, the 50-kDa antigen was identified as alkaline phosphatase (AP). Affinity-purified antibodies from patient's sera directed against the bacterial AP (anti-alpha) were also shown to react with human and animal AP, which have different structures. Anti-alpha are IgG subtype 3 immunoglobulins, and their light chains are of the kappa type. Upon isoelectric focussing, the anti-alpha formed a scalariform pattern with five to seven bands in the pH range 7-9. The anti-alpha have an opsonic activity and cause a five- to eightfold increase of phagocytosis of gram-positive and gram-negative bacteria. According to their polyreactivity, their sudden rise early in infection, their oligoclonality, as well as their opsonizing properties, they are assumed to be permanently available natural antibodies that take part in early defence mechanisms.